Sparking plug



Patented Dec. 23, 1924i.

FRANCIS LAYTON EL'JDREDGE, QF BURNEMOUTH, ENGLAND.

SPARKING PLUG.

Application tiled April 10, 1922. Serial No. 551,232.

To all whom t may concern.:

Be it known that I, FRANcIs LAY'roN .EL- DRIDGE, a subject of the Kingof Great Britain, residing at Bournemouth, Hampshire, England, haveinvented an Improved Sparking Plug, of which the following is aspecification.

This invent-ion relates to ignition devices for internal combustionengines of the type having a plurality of pairs of sparking points, onlyone pair being operable at a time While all the other pairs are cut outof communication With the engine cylinder and out of the operatingelectrical circuit.

One object of the present invention is to provide an ignition device ofthe type referred to having as few parts as possible. Another object ofthe invention is to construct such a device that it may be fitted toexisting sparking plug seatings or to the plug openings of enginecylinders. A further object is to provide a sparking plug in which asmuch as possible of the electrical connections are covered in, andanother object is to facilitate fixing electrodes in such sparkingplugs.

I Will now describe several constructions, by Way of example, embodyingthe present invention, With reference to the accompanying drawings, inWhich Fig. 1 is a sectional elevation of one form of plug;

Fig. 2 is an underside plan view of the construction shown in Fig. 1;

Fig. 3 is a section on the line 3 3 of Fig. 1;

Fig. 4 is an outside elevation of a modified form;

Fig. 5 is an underside plan View of the form shown in Fig. 4;

Fig. 6 is a sectional elevation of the construction shown in Fig. 4;

7 is a further underside vieuv of the construction shown in Figs. 4, 5or 6 showing an alternative position of the valve member;

Fig. 3 is a horizontal section on the line 3 8 of Fig. 6; and

Fig. 9 is a sectional elevation of a further modied form of theinvention.

Each of these constructions are characterized by tWo main parts, viz, aninsulating body formed With integral chambers, through each of whichdepend electrodes and an associated metal body provided with housings.adapted to register with the chambers aforecontinuation With thecentral perforation in F the body 11. llitliin the stem 15 is a seriesof separate housings 16 adapted to register With the chambers 13aforesaid. In each of the chambers is rigidly held an electrode 17,which depends from the body 11 and into a housing in the solid stem 15.The bottom of each housing is constricted, as at 1S, so as to furnishthe sparking point or points to operate With the elect-rode disposedtherein.

In the construction shown. a tubular nut 19 is provided and is adaptedto screw into the cup 14 in order to engage against the flange 12 andhold the insulating body Within the cup, but alternatively, the top ofthe cup may be sivage-d in over the bottom flange, although of course insuch construction repairs could not be effected Within the plug.

In order to provide means for shutting off all but one of the housingsfrom an associated combustion space, the bottom face of the metal bodyis formed as a seating for the valve 20 mounted on the spindle 21, thevalve having a single opening 22 dimensioned to register with theopening of a housing, While the rest of the valve covers the remaininghousings. rlhe position of the valve with regard to the housings isdetermined by rotating the control cap 23.

To accommodate the control cap 23, the top of the insulating body isformed with au annular ridge 24 at the top, on which bears a disc 25formed on the spindle 21 and fitted to the cap 23, the cap thus beinglined to the valve spindle 21 and disposed for rotation on the saidridge. `Within the ridge is arranged a spring 26 which is in compressionwhen the cap is fitted, the spring therefore functioning as a means forholding the valve 2O hard against its seating in order to formsubstantially a gas-tight joint.

In order to obtain a gas-tight joint, Where llt) each electrode adjoinsthe noot of thechamber in the-body l1, the electrode veilllbe providedWtli an annular or distance ring 27. and With a lead 28, whichisdisposedwithin the body 11. The outer end of the lead being providedwith a Contact plate 29,.which is screwed on to the lead 28 in order todraw the ring 27 tight against itis seating.

Preferably, the contact plates 29 are recessed,- and as indicated` inthe drawings, a nut forms a ery suitable contact plate.

In order to connect each contact plate Witlithek electrical supplysystem, a wiper 30 is provided whichmay llave a protuborance to registerWithin the recess infeach oon tact plate` 29; the` connect-*ionl ofthewipery tothe control cap* and" to-the high tension system is such` thatthe control cap canv be rotated Witliiir the Wiper. on\ top ot' any one`ci? the Contact plates Wit-hout straining the` connection between thehigh tension wire and the wiper.

In the construction shown, the wiper is provided with a` threadedportion 34 screwed? into' the control cap, andaispherical member 35,whichv is gripped between tuvo contacts- 36, 375, held in thetube 3B, towhichl ie also connected the high tension.- vv ire 391,. the contact'36' being lixed While the contact 3T. is

slidable ivitliin' tihe tube', andi under-cnt as at 40, to permitintroduction of' thel mem ber-35 through a slot1 or opening; in thetube, the contact 37 being held against the spher.- ical member 35 bymeans et ze spring 4:1? held inl compression by an adjustnbleplug 42;

Referring now to the modifications-shown in'y Figs. 4 to 8, theinsulating body isprovided'- intermediately of each contact nocess with'tu recess 43, into which tliew-.iper 30cm.- lgagesand in'y euch positionthe port 2Q ot thevaltfe-'QOldoesnot registerwvith any housing, so thatnone` of the electrodesare in use:

ln this construction the electnodes 1T are shown as screwed intio thebody, preferably obliquely, so that tlietop=portio1i:comesnear to theouter Walll oil the insulating body, this latterV beingv bared as;indicated* at. to exfpese tlie topfof the electrode, ai node 495 on. theWiper being adapted to fit into` they part lat to' formv electricalconueotion with the respective electrode.

A slightly modified construction is also employed with regardl to theconnection of the wiper to the control handle. 11n this construction theWiper iss-fixed by a screw to the insulating bodyand a lead t7 extendsaround the tcpy thereof to theV fixing element equivalent to themember34 shown in Fig. l.

In a; modification as show-n iny Fig. 9, the control cap is of suchdimension as to entirely overlap. the exposed ends of the electrodes,andV is screwedv on to the valve spindle 2l and fixed for rotationtherewith by a set screw 2P, and' in this construction a ball Contact 48is employedr on theinnor wall of the control: cap, the connection: tothe` electrical system being made through the spring 49the seatin50,.which.latter member preterably also p ufgs the boring made toreceive the ball and spring, and a lead 5l which is disposed within thebody of the control cap,. which;A is bored obliquely, as shown, in orderto receive it, this lead 51 being connectedI- to the member oli theelectrical system. In this hittery construction tlieie'ispractically no'vviroof theelectricall circuit exposedi From' tfhe` foregoingdescniption it willl be obsienvedsl that the rotation oli the-centralicap governs the position of the` wiper 3Q' and" the valve 20,V andI thatthese members are particularly connected so that when the opening 22inthe valve registers wit-li ahousing 1U, the wiper ouerlies tlliecontact platef connected to the electrode within` that housing, so thatsparking' muy oeeuv aft tlie- Contact points, wlrile at the some time`all the otherhousings aieetl'eetively closed and all the otherelectrodes are out out off the operative circuit.

The ignition device may be modiied by the introduction of washers suchas` 31, 32, or' 33 to render the plug gne-tight and*- toavoid injury tothe insulating body. By pnovidingfthe` chambers intheA insulate ingrbodav` and holdingir iiho elbetmodes well' up intothe chambers, asalready enplbined, any intermediate support adjacent the metal' body maybe eliminated, thereby preventing carbondeposits` bridging the spacebetween the electrodes and the' metnll wall-y o the housings, as wouldoceuirif distance pieces were arranged to steady the electrode new theymetalJ body.

I claim l. A sparking plug` o' the type referred to having incombinationan-insnlating-bmy havinga series ot' integrally formednellatively deep chambers, a metal body pevforatedi to form housingsinetension of said chambers, an electrode rigidly heldl in. the top ofeachy chamber and dependingjinto the respective housings, so as. to norma spark gap` at the open end' of each housing, a contact on the side ofsaid'l insulatlng body lion eaehi said` electrode,v a control'- cap`inountedf orrthe` insulatingbodgy, a ported valve adopted` to cov-en'all said) housings and to register with any one oif said housings when:thelplug is: in o oralzon. means connectin said valms to* sau` controlcap', a Wiper, to sweep e111 of said contacts, ependmg liront saidcontrol awp, and means connecting said wiper to an electrical circuit.

2. Ai sparking plug et the type: referred to, having in combination aninsulating body having a series. of integrallyA relatively deepchambers, a metal bodiy perk lll) lli

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forated to form housings in extension of said chambers, an electroderigidly held in the top of each chamber and depending into therespective housings, complementary spark points at the open end of eachhousing, a. contact on the side of said insulating body for each saidelectrode, a control cap mounted on the insulating body and overlappingthe body to cover all the said contacts, a Wiper fitted to the inner'Wall of said control cap and adapted to sweep all of said contacts, alead disposed in the body of said control cap for connecting said Wiperto an electrical circuit, a ported valve adapted to cover all saidhousings and to register with any one of said housings When the plug isin operation, and means connecting said valve to said control cap.

3. A sparking plug of the type referred to having in combination aninsulating body having a series of integrally formed relatively deepchambers, a metal body perforated to form housings in extension of saidchambers, each housing having a constricted end, an electrode rigidlyheld in the top of each chamber and depending through the respectivehousing and into the constricted end thereof to form an annular sparkgap, a contact on the side of said insulating body for each saidelectrode, a control cap mounted on the insulating body and overlappingthel body to cover all the said contacts, a Wiper fitted to the innerWall of said control cap and adapted to siveep all of said contacts, alead disposed in the body of said control cap for connecting said Wiperto an electrical circuit, a ported valve adapted to cover all thelconstricted ends of said housings and to register With any one of theconstricted ends When the plug is in operation, and moans connectingsaid valve to said control cap.

el. A sparking plug of the type referred to having in combination aninsulating body having a series of integrally formed relatively deepchambers, a flange near the bottoni of said insulating body, a metalbody comprising an internally threaded cup adapt-ed to receive theflanged end of the insulating body and a solid stem perforated to formhousings in extension of said chainbers, each housing having aconstricted end, a tubular member adapted to engage Within said cup andto hold the said insulating body againstsaid stem, an electrode rigidlyheld in the top of each chamber and depending through therespectivehousing and into the constricted end thereof to form an annular sparkgap, a contact on the side of said insulating body for each saidelectrode, a control cap mounted on the insulating body, and overlappingthe body to cover all the. said contacts, a Wiper fitted to the innerWall of said control cap and adapted to sweep all of said contacts, alead disposed in the body of said control cap for connecting said wiperto an electrical circuit, a ported valve adapted to cover all the saidconstricted ends of said housings, and to register With any one of saidconstricted ends, When the plug is in operation, and means connectingsaid valve to said control cap.

5. A, sparking plug of the type referred to having in combination aninsulating body having a series of integrally formed relatively deepchambers, a flange near the bottom of said insulating body, a metal bodycomprising an internally threaded cup adapted to receive the flanged endof the insulating body and a solid stem perforated to form housings inextension of said chambers, each housing having a constricted end, atubular member adapted to engage Within said cup and to hold the saidinsulating body against said stem, electrodes screwed into theinsulating body and disposed to depend from the top of said chambersthrough the respective housings and into the constricted ends thereof toform a series of annular spark gaps, a contact on the side of saidinsulating body for each said electrode, a control cap mounted on theinsulating body, and overlapping the body to cover all the saidcontacts, a Wiper fitted to the inner Wall of said control cap andadapted to sweep all of said contacts, a lead disposed in the body ofsaid control cap for connecting said Wiper to an electrical circuit, aported valve adapted to cover all the said constricted ends of saidhousings and to register With any one of said constricted ends, when theplug is in operation, and means connecting said valve to said controlcap.

6. A sparking plug of the type referred to having in combination aninsulating body having a series of integrally formed relatively deepchambers, a flange near the bottom of said insulating body, a metal bodycomprising an internally threaded cup adapted to receive the flanged endof the insulating body and a solid stem perforated to form housings inextension of said chainbers, each housing having a constricted end, atubular member adapted to engage Within said cup and to hold the saidinsulating body against said stein, electrodes screwed obliquely intothe insulating body so that the top portion comes near tothe outer Wallof the said insulating body and so as to depend from the top of saidchambers through the respective housings and into the oonstricted endsthereof to form a series of annular spark gaps, the said top portion ofeach electrode forming a respective cont-act therefor by the removal ofpart of the outer 'Wall of the insulating body to expose the said area,a control cap mounted on the inlll() sulnbinglmdy, andi omvlappngbhebody ho saidi Gunst-riuted ends of, said. housfupe, and Cowan all thesaid contacta a wipes; ttad bn homagister with any @ne Qi said;constriobad heinnan wwll'of-said conmolcapandiad L- and8,. when theplugisin: operation.,` and l0 edbo sweep wlhof saidaonbaots, a. leadze'meansonnaeting sia/idl value to said control f posed; in thabody ofsaidcontr-0L awp#- n cap.

connecting; said; wipen to any eleahrieal: oxx- Im'tsstimony whereof! Iax my signutur cuit, aportedavalive adapted tu cover al1 tha FRANGISLAYTQN ELDRIDGnEL

